Offers option to use meanspeed to calculate exit speed
Returned to 300s for Station Keeping challenge, and set to use the real arduino
updated the min and max exit speed values to be more realistic
Updated to better handle negative exitspeed values which may be initialized, and aren't yet updated by meanspeed, at the very beginning of the station keeping challenge
Removed annoying semi-colon from comment
Merge pull request #4 from UBCSailbot/new_exit_speed_method

New exit speed method